Two-way slit valve

ABSTRACT

A slit valve ( 10 ) for use with an inflatable medical device having a flange surface ( 12 ) with an opening therein. The slit valve ( 10 ) has a valve body ( 14 ) connected to the flange surface ( 12 ) and a chamber formed in the valve body ( 14 ) for accepting an inflation tube ( 34 ) inserted through the opening in the flange surface ( 12 ). The slit valve ( 10 ) has a concave section at one or both ends, which are connected by a slit ( 24 ) formed in the valve body ( 14 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to a slit valve that enables two-wayfluid flow, and in particular a slit valve for use with implantable,inflatable medical devices such as a gastric balloons for the treatmentof obesity.

2. Description of the Related Art

There are a wide variety of known inflatable devices that can beimplanted in the body.

One such inflatable implantable medical device is a gastric balloon, asdescribed in U.S. Pat. No. 5,084,061, or commercially available as theBioEnterics Intragastric Balloon System (sold under the trademark BIB®).These devices are designed to provide therapy for moderately obeseindividuals who need to shed pounds in preparation for surgery, or aspart of a dietary or behavioral modification program.

The BIB System, for example, consists of a silicone elastomer gastricballoon that is inserted into the stomach and filled with fluid.Commercially available gastric balloons are filled with saline solutionor air. The gastric balloon functions by filling the stomach andenhancing appetite control. Placement of the gastric balloon isnon-surgical, usually requiring no more than 20-30 minutes. Theprocedure is performed endoscopically in an outpatient setting, usinglocal anesthesia and sedation. Placement is temporary, and gastricballoons are typically removed after six to twelve months.

There are known in the prior art a variety of valves for use with suchgastric balloons. For example, the valve described in U.S. Pat. No.5,084,061, shown in FIG. 1, consists essentially of a leaf valve (alsoknown as a duckbill valve) comprising two relatively flat pieces ofsilicone elastomer bonded along their longitudinal edges and affixed byadhesive to the end of the valve stem. In operation, a filler tube,which is usually a plastic or silicone tube containing a stainless steelstiffening rod, is inserted through an X-shaped slot, through a hole,through a tubular valve stem, through a second X-shaped slot in themembrane, and through the leaf valve until the filler tube itself is inthe interior of the shell. In such a position, both addition andwithdrawal of fluid can be accomplished. For addition of fluid only, thefiller tube does not need to penetrate through the leaf valve.

However, valves of this sort have several disadvantages. Initially,these valves are prone to leaking. One way in which a duckbill valve maydevelop leaks is through the initial filling of the balloon when one ofthe flat pieces of elastomer becomes kinked or develops a curvaturethrough which the fluid can pass. Another way is through the fluidremoval process, which requires the insertion of the filler tubecompletely through the valve and into the interior of the shell.Following removal of a portion of the fluid and the filler tube, theleaf valve can remain partially open. This causes even greater amountsof the fluid to be released from the implant. Accordingly, there is aneed for a valve that does not leak following either filling or removalof fluid from the shell.

Second, the prior art leaf valves face opposing problems in that it isnecessary to reduce the pressure necessary to insert the filler tubeinto the valve to ease in installation and filling, but if there is nota sufficiently tight fit between the filler tube and the valve, then thepressure of the fluid in the balloon or valve may force the filler tipout of the valve before filing is complete. Further, it is necessary toconsider the amount of force necessary to remove the fill tube from thevalve. Current designs, such as that discussed above, often require toomuch pressure to insert the filler tube into the valve and too muchpressure to remove the filler tube from the valve. Alternatively, ininstances where the pressure necessary to insert and remove the fillertube are not great, the filler tube may pop out of the valve whilefilling the balloon. Accordingly, there is a need for a valve thatpromotes easy insertion and removal of the filler tube, but does notforce the filler tube out of the valve while filling the balloon. Priorart leaf valves are also unsuitable at fluid inflation pressures above30 psi, which may damage the valve.

Finally, the prior art duckbill valves have the shortcoming that theyare only one-way valves. They cannot be used to direct fluid flow inboth directions without inserting a tube completely through the valve.Situations arise where it is preferable to have a two-way valve. Forexample, when a device absorbs additional fluid through osmosis afterbeing implanted in the body and filled to a proper volume, it may bedesirable to reduce the fluid volume of that implant. In the duckbillvalve described above, no amount of pressure on the interior of theballoon will permit egress of the fluid contained therein. Accordingly,there is a need to a valve that is capable, of permitting back flow offluid (i.e. from the interior to the exterior), while generallypreventing egress of fluid when under normal pressure.

Another type of valve often used in implant technology is a diaphragmvalve, such as a that discussed in U.S. Pat. No. 6,419,699 assigned toMcGhan Medical Corporation. The diaphragm valve requires insertion of arigid male component on the inflation tube to open the valve and allowfluid transfer. Upon removal of the inflation tube, fluid pressurewithin the implant forces the valve closed and creates a leak proofseal. As with the leaf valve, such a valve does teach any means forbackflow through the valve.

Other valves that are used in medical applications include a connectorfor an instrument insertion passage described in U.S. Pat. No. 5,599,327(“the '327 patent”), a non-binding surgical valve as described in U.S.Pat. No. 5,916,198 (“the '198 patent”), and a needle less injection siteas described in U.S. Pat. No. 6,261,268 (“the '268 patent”). Each ofthese valves or connectors has shortcomings that are addressed by thepresent invention. Initially, both the '327 and the '268 patentscontemplate an opening in the valve that forms a seal with theapplication of mechanical pressure by a medical instrument. Accordingly,both the '327 and '268 patents require the use of bulky components andmechanical force to create a seal. Such components and use of mechanicalforce are not conducive for use with implant technology. Further, the'198 patent describes a one-way valve that is closed by insufflationgases acting on an interior surface of the valve via a passage in one ofthe valve segments. Accordingly, the valve contemplated by the '198patent does not overcome the shortcomings of the prior art discussedabove.

Therefore, the present invention is directed at overcoming theseproblems associated with the prior art valves. The present invention isrelated to a two-way valve that is usable in an implantable medicaldevice such as a gastric balloon.

These and other characteristics of the present invention will becomeapparent from the further disclosure to be made in the detaileddescription given below.

SUMMARY OF THE INVENTION

The present invention is directed to a two-way valve having first andsecond ends. The two-way valve includes a substantially cylindricalvalve body having a slit connecting the first and second ends of thevalve and concave sections formed in the first and second ends.

The present invention is further directed to a slit valve having aflange surface with an opening therein. The slit valve has a valve bodyconnected to the flange surface and a chamber formed in the valve bodyfor accepting an inflation tube inserted through the opening in theflange surface. The slit valve has a concave section at one or bothends, which are connected by a slit formed in the valve body.

The present invention is also directed to an implantable, inflatableapparatus having a slit valve. The slit valve includes a flange surfacehaving an opening. The slit valve also includes a valve body connectedto the flange surface, a first chamber formed in the valve body foraccepting an inflation tube inserted through the opening in the flangesurface, a concave section located at one or both ends of the valve, anda slit formed in the valve body connecting the two ends.

The present invention is also directed to a medical apparatus for thetreatment of obesity. The medical apparatus includes a balloon formed ofa suitable polymer or elastomer material for insertion into the stomach,and a slit valve for communication of a fluid from an inflation tube tothe balloon. The slit valve includes a flange surface having an openingtherein, a valve body connected to the flange surface, a first chamberformed in the valve body for accepting the inflation tube insertedthrough the opening in the flange surface, a concave section located atone or both ends of the valve, and a slit formed in the valve bodyconnecting the two ends.

Further characteristics, features, and advantages of the presentinvention will be apparent upon consideration of the following detaileddescription of the invention taken in conjunction with the followingdrawings, and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of a prior art gastric balloon with aone-way valve;

FIG. 2 is a cross-sectional view of a prior art one-way valve;

FIG. 3 is a side view of a two-way slit valve according to one of theembodiments of the present invention;

FIG. 4 is a cross-sectional view of the two-way valve shown in FIG. 3;

FIG. 5 is a close-up view of a portion of the two-way valve shown inFIG. 4;

FIG. 6 is a top view of the two-way valve according to another aspect ofthe present invention;

FIG. 7 is side view of a filler-tube according to another aspect of thepresent invention;

FIG. 8 is a side view of an inflation tip according to another aspect ofthe present invention;

FIG. 9 is a cross-sectional view of the inflation tip of FIG. 8; and

FIG. 10 is a cross-sectional view of a two-way valve according toanother aspect of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A slit valve 10 in accordance with a first embodiment of this inventionis shown in FIG. 3. The valve comprises a valve body 14 and a flange 12.With respect to the description of this invention, the end of the valve10 on which the flange 12 is located will be called the top of the valveand the opposite end the bottom. The valve 10 is preferably formed of anelastomeric material such as silicone, however, other materials may beused without departing from the scope of this invention. The valve body14 is preferably molded in a substantially cylindrical shape. Thecylindrical shape is preferred as it provides added rigidity andstiffness for the valve.

FIGS. 4 and 5 show cross-sectional views of the valve 10. FIG. 6 shows atop view of valve 10. Starting at the flange surface 12 of the top ofthe valve 10, there is an opening 16 through the flange 12 that is incommunication with interior surfaces of the valve 10. Immediately belowthe opening 16 is a first chamber 18. Beneath the first chamber 18 is aneck 19. The neck 19 separates the first chamber 18 from a secondchamber 26. At the bottom of the second chamber is a concave surface 20.The concave surface 20 is preferred because it provides guidance to aprobe in the event that the sealing properties of valve 10 need to beovercome mechanically. The concave surface 20 assists in the guidance ofa probe (not shown) that can be used to force the valve to open andallow for reverse flow of fluid contained by the valve 10.

Following the concave surface 20 is a slit 24 in a substantially solidportion of the body 14. The slit 24 connects and is in fluidcommunication with a second surface 22, which may be concave as shown,or flat. In an application such as a gastric balloon, fluid enters theballoon shell as it exits the bottom side of the slit 24. The slit 24may be lubricated with silicone oil. The use of silicone oil eases theinsertion of a removal tip (not shown) in instances where it is desiredto overcome the sealing properties of the valve 10, and serves to reducethe chance of cross-linking where the valve body 14 is made of silicone.

FIG. 7 depicts a filler tube 30. The filler tube is comprised of a longflexible tube 34 having a lumen therethrough, an injection tip 32, and aconnector 35 for connecting the filler tube to a fluid supply (notshown). The flexible tube 34 may be provided with reference lengthmarkers 36 to provide medical personnel with a visual indication of theposition of fill tube 30 inside the patient. As shown in FIGS. 8 and 9,the injection tip 32 has an orifice 37 extending therethrough thatallows for fluid communication through the flexible tube 34, and theinjection tip 32. One of the ends of the injection tip may be taperedinto a wedge shape 38 having its smallest cross-section at the distalend of the injection tip 32. The wedge shape 38 assists in the insertionof the injection tip 32 into slit valve 10. Further, the injection tipmay include a reduced diameter portion 40, and an insertion stop 42 forpositively engaging the opening 16 of valve 10. The other end of theinjection tip 32 is provided with barbs 44 to retain flexible tube 34 influid-tight engagement with the injection tip.

In use, the filler tube 30 is connected to the valve 10 by inserting theinjection tip 32 into opening 16 of the valve 10. The injection tip 32,upon full insertion into the valve, extends to a point approximatelyeven with a top surface of the second chamber 26. The substantial wedgeshape 38 of the injection tip matches the orientation of the firstchamber 18, and the narrow cross-sectional portion of the injection tip32 is held firmly by the neck 19 of valve 10 to form a seal preventingthe egress of fluid from the second chamber 26 into the first chamber 18and out through the opening 16. The insertion stop 42 on the injectiontip 32 prevents the injection tip from being inserted into the valve 10beyond a pre-determined point. Upon full insertion, the insertion stop42 rests against the flange 12 of valve 10. The opening 16 is of a sizethat, upon insertion of the injection tip 32, a second seal is formed bythe interference of the flange 12 and the reduced diameter portion 40 ofthe injection tip. This second seal further insures that fluid does notexit the valve 10 and prevents other contaminants from entering thevalve 10.

The valve 10 may be attached to an inflatable medical device such as agastric balloon, a mammary implant, such as a Becker-style breastimplant, a tissue expander, or the like. Other non-inflatableapplications of the valve include devices such as a shunt drug deliveryor therapeutic delivery system, a feeding tube, or the like.Accordingly, these variations are contemplated within the scope of thepresent invention. Where the device is a gastric balloon, the valve 10is attached to the shell substantially as shown in Prior Art FIGS. 1 and2. The flange surface 12 is placed flush with the exterior surface ofthe balloon and may be covered by an elastomeric sheath material thatbonds the components together forming an integral gastric balloon andvalve combination. The gastric balloon is inserted into a patient in adeflated state and inflated after insertion. Following insertion of thegastric balloon, a fluid, typically sterile saline, is injected into thegastric balloon via the filler tube 30. Other fluids, including air,silicone, pseudogel, oil, etc., may be used to fill an implant.

To inflate the gastric balloon, the valve 10 must have a slit 24. Theslit 24 is preferably a single separation of two sides of the valve body14. The slit 24 is formed during manufacturing by inserting a sharp thintool (not shown) into the valve body 14. The length of the slit 24 isvariable depending on the application of the valve and the desiredopening pressure of the valve. In certain applications it may benecessary to insure that slit valve permits backflow more readily. Insuch instances, a shorter slit length would be used, whereas ininstances where greater pressure must be contained by the valve, alonger slit length is desirable.

To effectuate inflation via the filler tube 30, the injection tip 32 isinserted into the opening 16 of the flange 12. The distal end ofinjection tip 32 extends to form a seal with neck 19. When pressurizedfluid is injected through the filler tube 30 and orifice 37 of theinjection tip 32, a higher pressure is created in the second chamber 26having two effects. The first is to increase the sealing pressure of theneck 19 on the injection tip 32. The second effect is to force the slit24 to open. The decreased wall thickness of the valve body 14 in thearea of the second chamber 26 is more readily deformed by thepressurized fluid injected into the second chamber 26 than the area ofthe slit 24. The increased pressure causes the second chamber 26 toexpand in a direction substantially perpendicular to the direction ofthe slit 24. This expansion in turn causes the slit 24 to be opened andpermits the flow of fluid from the second chamber 26 through the slit 24and into the implant. The opening of the slit is assisted by the concavesurface 20. Similarly, if the second surface 22 is also concave,sufficient pressure may be applied to the shell to overcome the backflowresistance of the valve to permit the flow of fluid through the slit 24to the exterior of the implant. Due to the relative sizes of the secondchamber 26 and the concave surface 22, a far greater pressure isrequired to permit the backflow of fluid from the implant out of thevalve than is required for inflation. For this reason the balloon orother implant may also be deflated or reduced in volume by inserting asmall diameter probe or tube completely through the valve and into theinterior of the implant shell. Concave surface 20 assists in guiding thesmall-diameter probe or tube into and through the valve body 14.

The valve 10 and the filler tip 32 when used in combination create asystem that overcomes many of the shortcomings of the prior art. Throughthe use of the opening 16 and its interaction with the reduced diameterportion 40 of the injection tip 32, and also because of the interactionof the neck 19 with the injection tip 32, the injection tip is heldfirmly in place and is prevented from being forced out of the valve 10during the injection of fluid through the valve 10. Further, because ofthese same features, withdrawal of the injection tip 32, when desired bythe user, is greatly eased requiring less than 4 lb (17.8 N) of force toremove the tip from a balloon filled to 700 cm³. Still further, thevalve 10 provides for a device that does not leak under normal operatingconditions yet still allows for two-way flow. The valve of the presentinvention allows continuous fluid flow at 30 psi (2.11 Kg/cm²) and cansafely withstand fluid fill pressures of up to 40 psi (2.81 Kg/cm²)without damage to the valve.

FIG. 10 depicts another aspect of the present invention. FIG. 10 shows avalve 11 having many of the features of the valve 10 shown in FIGS. 3-6.Valve 11 has a first concave surface 20, a second concave surface 22,and a slit 24, all housed in a body 14. The valve 11 operates in asimilar fashion to valve 10. Upon application of a predetermined fluidpressure to one of either the first or second concave surfaces, 20 or22, the slit 14 will open and allow fluid to pass. However, at pressuresbelow the predetermined value, the slit valve insures that there is nofluid flow. The relative geometries of the concave surfaces 20, 22, thelength of the slit 24, and the valve body 14 determine the openingpressure of the valve 11 and whether a greater pressure is required forflow in one direction compared to flow in the other direction. Such avalve would be useful in applications where the use of a flange 12, asshown in FIG. 3, is undesirable or unfeasible, for example in a feedingtube or a drug delivery shunt.

Although the invention has been particularly shown and described withreference to certain preferred embodiments, it will be readilyappreciated by those of ordinary skill in the art that various changesand modifications may be made therein without departing from the spiritand scope of the invention.

1. A slit valve for a medical implant for accepting an inflation tube,the valve comprising: a unitary valve body having a proximal end and adistal end; a flange at the proximal end of the valve body and having aflange opening therein; a first chamber defined in said valve body andin open fluid communication with the flange opening, the first chamberbeing capable of accepting an inflation tube when inserted through saidflange opening; a second chamber having a concave section, the secondchamber located between said said first chamber and said distal end ofthe valve body; and a normally closed slit formed in the valve body andconnecting the concave section and the distal end of the valve body;wherein the valve body is structured to receive an inflation tubethrough the flange opening whereby fluid introduced from the inflationtube into the second chamber causes the slit to open and pass distallythrough the distal end of the valve body.
 2. The valve of claim 1,wherein, upon insertion of an inflation tube, said flange openingaccepts a tip portion of the inflation tube and secures the tip in saidvalve.
 3. The valve of claim 2, wherein said tip portion has a reduceddiameter part and, upon passage of the tip portion of the inflation tubethrough said flange opening, said opening engages the reduced diameterpart of the tip portion of the inflation tube thereby securing the tipportion in said valve.
 4. The valve of claim 1 further comprising a neckportion between the first chamber and the second chamber, wherein uponinsertion of an inflation tube, a tip portion of the inflation tubeengages said neck portion.
 5. The valve of claim 4, wherein the neckportion is such that, upon said insertion of the inflation tube, atleast a portion of said neck portion substantially conforms to the shapeof the tip portion of the inflation tube.
 6. The valve of claim 1,wherein said distal end further comprises a concave section.
 7. Thevalve of claim 6, wherein upon application of fluid pressure to theconcave section of the distal end, the slit opens permitting fluid topass therethrough and through said proximal end of said valve body. 8.The valve of claim 1, wherein the length of said slit corresponds to adesired opening pressure of the valve.
 9. An implantable, inflatableapparatus comprising: an inflatable portion; and a slit valve secured tothe inflatable portion, the slit valve including a unitary valve bodyhaving a proximal end and a distal end, a flange at the proximal end ofthe valve body and having a flange opening therein, a first chamberdefined in said valve body and in open fluid communication with theflange opening, the first chamber being capable of accepting aninflation tube when inserted through said flange opening, a secondchamber having a concave section, the second chamber located betweensaid said first chamber and said distal end of the valve body, anormally closed slit formed in the valve body and connecting the concavesection and the distal end of the valve body, wherein the valve body isstructured to receive an inflation tube through the flange openingwhereby fluid introduced from the inflation tube into the second chambercauses the slit to open and pass distally through the distal end of thevalve body.
 10. The apparatus of claim 9, wherein the apparatus is agastric balloon.
 11. The apparatus of claim 9, wherein the apparatus isa mammary implant.
 12. The apparatus of claim 9, wherein the apparatusis a tissue expander.
 13. The apparatus of claim 9, wherein, uponinsertion of an inflation tube, said flange opening accepts a tipportion of the inflation tube and secures the tip in said valve.
 14. Theapparatus of claim 13, wherein said tip portion has a reduced diameterpart and, upon passage of the tip portion of the inflation tube throughsaid flange opening, said opening engages the reduced diameter part ofthe tip portion of the inflation tube thereby securing the tip portionin said valve.
 15. The apparatus of claim 13, wherein at least a portionof said first chamber substantially conforms to the shape of the tipportion of the inflation tube.
 16. The apparatus of claim 9 furthercomprising a neck portion located between the first chamber and thesecond chamber, wherein upon insertion, a tip portion of the inflationtube engages said neck portion.
 17. The apparatus of claim 9, whereinsaid distal end further comprises a concave section.
 18. The apparatusof claim 17, wherein upon application of fluid pressure to the concavesection of said distal end, said slit opens permitting backflow throughsaid valve.
 19. The apparatus of claim 9, wherein the length of saidslit corresponds to a desired opening pressure of the valve.
 20. Theapparatus of claim 9, for the treatment of obesity, wherein theinflatable portion is in the form of an implantable balloon formed of asuitable polymer material for insertion into the stomach.